Proteoglycan aggregates, proteoglycan monomers and link proteins are to be isolated from bovine epiphyseal cartilages, and chemically and physically characterized to provide a basis for demonstrating the structural changes in proteoglycans which occur when a non-calcifiable matrix is transformed into a calcifiable matrix. A soluble, functional oligomeric form of link protein will be physically characterized. Antibodies will be raised to fetal epiphyseal proteoglycan monomer and link protein. The localization of these species in the zones of proliferating chondrocytes, hypertrophic cells and calcified cartilage will be determined to examine the existing hypothesis that these species are degraded by proteases when mineral deposition occurs in intercellular matrix. An attempt will be made to elucidate the mechanism whereby the intercellular matrix in epiphyseal cartilage growth plate is transformed from a non-calcifiable into a calcifiable matrix.